Future of Lupus Treatments Looks Brighter With Multiple Promising Therapeutic Approaches
FROM EULAR 2024
VIENNA — It may have been a while since there have been any major breakthroughs in the treatment of systemic lupus erythematosus (SLE), but there are high hopes that this is a situation that may be about to change, experts agreed at the annual European Congress of Rheumatology.
“It’s an incredibly vivid area of development,” Laurent Arnaud, MD, PhD, professor of rheumatology at the University of Strasbourg in Strasbourg, France, said during one of the first sessions of the meeting. He reported that there were at least 17 phase 2 and 14 phase 3 trials that were expected to start within the next few years, all with investigational agents that target different immune cells or pathways that have been implicated in the pathogenesis of SLE.
In a systematic review published last year, Dr. Arnaud and coauthors found that there were 92 investigational biologic or novel targeted agents in various phases of clinical testing. This included B-cell–targeting agents such as ianalumab, plasma cell-targeting agents such as daratumumab, and drugs with novel mechanisms of action such as KPG-818, which targets the CRL4-Cereblon (CRBN) E3 ubiquitin ligase complex. Phase 2 data on all three of these investigational agents were presented during various sessions at EULAR 2024, all with positive results, suggesting that their further development in SLE is worth pursuing.
There are of course “many more candidates in the pipeline,” Dr. Arnaud said. “I’m very happy that I think we are going to see great days for lupus right in front of our eyes.”
Targeting B Cells
Drugs that target B cells have been at the forefront of lupus treatment for several years, as David Isenberg, MD, professor of rheumatology at University College London, pointed out during an interview for EULAR TV.
“It’s clearly important to target the cells which are likely to be causing the problem in lupus, and in the main, that tends to be B cells,” he said.
Dr. Isenberg, who is renowned for his work with the B-cell–targeting agent rituximab, added: “But we know that obviously T cells integrate with B cells, so anything which interrupts the link between the T cell and the B cell is likely to be important.”
Chimeric Antigen Receptor (CAR) T-Cell Therapy ‘Revolution’
One new way of targeting B cells is with CAR T-cell therapy, which David D’Cruz , MD, PhD, a consultant rheumatologist for Guy’s and St. Thomas’ Hospital NHS Foundation Trust in London, picked as one of the “most striking” topics highlighted at EULAR 2024.
This is “truly personalized medicine,” Dr. D’Cruz said. This is an autologous therapy because a patient’s T cells are removed by leukapheresis, transfected with a CAR T vector directed against a component of the B cell, and then returned to them.
“I do feel that we’re on the cusp of a major revolution,” Dr. D’Cruz told this news organization. Not only in lupus but also in other rheumatic conditions that have proved really difficult to treat, such as systemic sclerosis and myositis, he said.
“Basically, it’s a very powerful B-cell–depleting tool, but it’s much more profound B-cell–depleting tool than, for example, rituximab or belimumab,” explained Dr. D’Cruz. “What you’re doing is reprogramming T cells to attack the B cells.”
Although rituximab and belimumab clear all the B cells in the circulation, there are still some cells left behind in the bone marrow, “and it’s very difficult to get rid of those,” Dr. D’Cruz said. “What CAR T-cell therapy appears to do is wipe out all the CD19-positive B cells everywhere, in the blood and the tissue. So you get a really profound B-cell depletion.”
Eric Morand, MBBS, PhD, head of rheumatology at Monash Health in Melbourne, Australia, told this news organization that there was obviously “a lot of buzz” about CAR T-cell therapy.
“We’re waiting to see if the exciting data from Erlangen can be reproduced in other centers with other CAR T products to show that it is a universal effect. We haven’t seen that yet, but I think we will by next year.”
Cost and expertise are two major considerations and potential limiting factors, however, as Dr. D’Cruz and Dr. Isenberg both pointed out in separate interviews with this news organization.
Dr. D’Cruz said: “It’s very expensive, it takes a while, and it doesn’t always work is what I’m hearing. It’s usually successful, but again, a little bit depends on the technique and the people doing the process.”
Dr. Isenberg said: “CAR T-cell therapy is, I think, very exciting because it does look to be quite promising. But as it costs 350,000 euros per patient, I don’t think that it is going to be widely adopted.”
Even if it could be afforded by certain centers in the West, he added, this just would not be feasible in poorer nations. “So, we’ve got to find other effective, cheaper ways to go,” Dr. Isenberg said.
“I think there are some very interesting ideas with monoclonal antibodies which target at least two different targets — one on the B cell, one on the T cell — and that could well be the way to take this forward,” he suggested.
